It really depends on the plate actual hardness, level of deformation, and setup for the bend. After that, the calculation is done based on conventional structural mechanics - instead of the deformation limit must be observed to avoid cracking. Hard to explain over the internet - better have someone to take a look at the local if its a critical operation. If it is not - a backyard project or so, just calculate the force by considering a simplified diagram with the geometry of the bend you want and add a good "safety" margin.
force
Re: force
